Memo: Sea Level Rise Analysis for Eureka-Arcata Corridor

This memo documents the rationale for decisions Caltrans made regarding the Eureka – Arcata Route 101 Corridor Improvement Project and long-term Sea Level Rise (SLR) planning for U.S. Highway 101 (US 101) between Eureka and Arcata. This memo begins with immediate design decisions regarding heights of structures on this current safety project, and then begins discussing various considerations for long-term planning

Caltrans Eureka-Arcata Corridor: Sea Level Rise Vulnerabilities and Adaptation Solutions

Caltrans is proposing to improve unsafe portions of the Highway 101 Eureka-Arcata Corridor (the Corridor). This includes the Indianola Road / Highway 101 Intersection, Jacoby Creek Bridge, and four tide gates. In this report, the vulnerability of the proposed Caltrans projects to SLR and other coastal hazards is analyzed. The analysis enables identification of a range of adaptation options for the proposed projects

Caltrans Climate Change Vulnerability Assessment, District 1 - Technical Report

The following report summarizes a vulnerability assessment conducted for that portion of the State Highway System (SHS) located in Caltrans District 1. The vulnerability study had three objectives: (1) Understand the types of weather-related and longer-term climate change events that will likely occur with greater frequency and intensity in future years, (2) Conduct a vulnerability assessment to determine those Caltrans assets vulnerable to various climate-influenced natural hazards, and (3) Develop a method to prioritize candidate projects for actions that are responsive to climate change concerns, when financial resources become available

6. PERFORMING ORGANIZATION CODE

This report has been prepared as the final deliverable for Phase II of a project for the California Department of Transportation to develop a combined quantitative and qualitative approach for planning for improved intermodal connectivity at California airports. The objectives of this phase were to further develop the Intermodal Airport Ground Access Planning Tool (IAPT) to improve its functionality, to estimate updated versions of mode choice models for use with the IAPT, to correct errors in the calculation of performance parameters by the IAPT, and to conduct a case study as a test of the IAPT. The objective of developing the IAPT is to provide a standard, transparent and scientific way for quantitative airport ground access project evaluation at the airport level. A user-friendly graphical interface makes it easy for a user to run the model in the following sequence of steps: (a) to define performance measures and the associated transportation service data variables for the different modes involved; (b) to select a

Evaluating the long-term impacts of bus-based park and ride

Many park and ride (P&R) schemes worldwide are based on rail transport, however there has also been substantial development of bus-based P&R in which an enhanced bus service operates between a P&R site and an urban centre. This has been particularly marked in Britain, often in historic cities (such as York, Oxford and Cambridge). Development of busways has also provided opportunities for complementary P&R development. Nonetheless, a net increase in passenger car unit (pcu)-kilometres may be observed, despite a reduction on the principal radial corridor. This is due to increased car-kilometres in catchment areas of P&R sites, but this simple additive approach to changes in pcu-km may not reflect overall impacts if pcu-km are removed from a congested urban corridor. By using monetised external cost per pcu-km for different road types and traffic conditions (such as those in ‘WebTAG’ guidance in Britain), the net effect can be expressed in economic terms. Presented here is a case study of the Chelmsford system, showing that a net economic benefit may be attained, even though a net increase in pcu-km has occurred. Energy savings through diversion of car occupant trips to the Cambridgeshire busway are also assessed

Seismic response analysis of multiple-frame bridges with unseating restrainers considering ground motion spatial variation and SSI

Unseating damages of bridge decks have been observed in many previous major earthquakes due to large relative displacement exceeding the available seat length. Steel cable restrainers are often used to limit such relative displacements. Present restrainer design methods are based on the relative displacements caused by the different dynamic characteristics of adjacent bridge structures. However, the relative displacements in bridge structures are not only caused by different dynamic characteristics of adjacent bridge segments. Recent studies indicated that differential ground motions at supports of bridge piers and Soil Structure Interaction (SSI) could have a significant influence on the relative displacement of adjacent bridge components. Thus the present design methods could significantly underestimate the relative displacement responses of the adjacent bridge components and the stiffness of the restrainers required to limit these displacements. None of the previous investigations considered the effects of spatially varying ground motions in evaluating the adequacy of the restrainers design methods. Moreover, the code recommendation of adjusting the fundamental frequencies of adjacent bridge structures close to each other to mitigate relative displacement induced damages is developed based on the uniform ground motion assumption. Investigations on its effectiveness to mitigate the relative displacement induced damages on the bridge structures subjected to spatially varying ground motion and SSI are made. This paper discusses the effects of spatially varying ground motions and SSI on the responses of the multiple-frame bridges with unseating restrainers through inelastic bridge response analysis

The Effects of Long-Duration Subduction Earthquakes on Inelastic Behavior of Bridge Pile Foundations Subjected to Liquefaction-Induced Lateral Spreading

Effective-stress nonlinear dynamic analyses (NDA) were performed for a large-diameter reinforced concrete (RC) pile in multi-layered liquefiable sloped ground. The objective was to assess the effects of earthquake duration on the combination of inertia and liquefaction-induced lateral spreading. A parametric study was performed using input motions from subduction and crustal earthquakes covering a wide range of motion durations. The NDA results showed that the pile head displacements increased under liquefied conditions, compared to nonliquefied conditions, due to liquefaction-induced lateral spreading. The NDA results were used to develop a displacement-based equivalent static analysis (ESA) method that combines inertial and lateral spreading loads for estimating elastic and inelastic pile demands

Flood fragility analysis for bridges with multiple failure modes

Bridges are one of the most important infrastructure systems that provide public and economic bases for humankind. It is also widely known that bridges are exposed to a variety of flood-related risk factors such as bridge scour, structural deterioration, and debris accumulation, which can cause structural damage and even failure of bridges through a variety of failure modes. However, flood fragility has not received as much attention as seismic fragility despite the significant amount of damage and costs resulting from flood hazards. There have been few research efforts to estimate the flood fragility of bridges considering various flood-related factors and the corresponding failure modes. Therefore, this study proposes a new approach for bridge flood fragility analysis. To obtain accurate flood fragility estimates, reliability analysis is performed in conjunction with finite element analysis, which can sophisticatedly simulate the structural response of a bridge under a flood by accounting for flood-related risk factors. The proposed approach is applied to a numerical example of an actual bridge in Korea. Flood fragility curves accounting for multiple failure modes, including lack of pier ductility or pile ductility, pier rebar rupture, pile rupture, and deck loss, are derived and presented in this study.ope

Managed Aquifer Recharge as a Tool to Enhance Sustainable Groundwater Management in California

A growing population and an increased demand for water resources have resulted in a global trend of groundwater depletion. Arid and semi-arid climates are particularly susceptible, often relying on groundwater to support large population centers or irrigated agriculture in the absence of sufficient surface water resources. In an effort to increase the security of groundwater resources, managed aquifer recharge (MAR) programs have been developed and implemented globally. MAR is the approach of intentionally harvesting and infiltrating water to recharge depleted aquifer storage. California is a prime example of this growing problem, with three cities that have over a million residents and an agricultural industry that was valued at 47 billion dollars in 2015. The present-day groundwater overdraft of over 100 km3 (since 1962) indicates a clear disparity between surface water supply and water demand within the state. In the face of groundwater overdraft and the anticipated effects of climate change, many new MAR projects are being constructed or investigated throughout California, adding to those that have existed for decades. Some common MAR types utilized in California include injection wells, infiltration basins (also known as spreading basins, percolation basins, or recharge basins), and low-impact development. An emerging MAR type that is actively being investigated is the winter flooding of agricultural fields using existing irrigation infrastructure and excess surface water resources, known as agricultural MAR. California therefore provides an excellent case study to look at the historical use and performance of MAR, ongoing and emerging challenges, novel MAR applications, and the potential for expansion of MAR. Effective MAR projects are an essential tool for increasing groundwater security, both in California and on a global scale. This chapter aims to provide an overview of the most common MAR types and applications within the State of California and neighboring semi-arid regions